Perhaps you should try some spelling variations:
"python missing data snippets" » "python using data snippets"
"locating bug core snippets" » "locating bug code snippets"
"da tu hoc snippets" » "da tu code snippets", "da te hoc snippets", "dau tu hoc snippets", "dan tu hoc snippets", "dai tu hoc snippets"

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (((("da tu hoc snippets") OR ("python missing data snippets"))) OR ("locating bug core snippets"))~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "((((\"da tu hoc snippets\") OR (\"python missing data snippets\"))) OR (\"locating bug core snippets\"))".
• Removing quotes may allow a broader search: (((( da tu hoc snippets ) OR ( python missing data snippets ))) OR ( locating bug core snippets )).
• Adding a wildcard symbol may retrieve word variants: (((("da tu hoc snippets") OR ("python missing data snippets"))) OR ("locating bug core snippets"))*.